A Gmail outage that lasted about 30 hours and affected some Google Apps customers was finally fixed late on Thursday.

At around 9:30 p.m. U.S. Eastern Time, a Google spokesman said via e-mail that the problem had been solved. He offered no details about its cause nor an explanation about why it took Google so long to fix it. The spokesman said the problem affected "a small number" of Gmail users, but declined to be more specific.

The first problem reports started appearing in the official Google Apps discussion forum around mid-afternoon Wednesday. At around 5 p.m. that day, Google acknowledged that the company was aware of a problem preventing Gmail users from logging into their accounts and that it expected a solution by 9 p.m. on Thursday.

In companies that were affected, Apps administrators told of very tense situations, in some cases involving having to deal with extremely upset CEOs and other high ranking executives who got locked out of their e-mail.

Google Apps is a suite of hosted collaboration and communication software and services designed for workplace use. Its Standard and Education versions are free. Its more sophisticated Premier edition costs US$50 per user per year and includes a 99.9 percent uptime guarantee for the Gmail service.

In August, Gmail had three significant outages that affected not only individual consumers of the free Webmail service but also paying Google Apps Premier customers. As a result, Google decided to extend a credit to all Apps Premier customers and said it would do better at notifying users of problems.

One outage, on Aug. 11, lasted about two hours but affected almost all Apps Premier users. The other two, on Aug. 6 and Aug. 15, hit a small number of Apps Premier users, but both outages were lengthy, affecting some users for more than 24 hours. In all of the incidents, users were unable to access their Gmail accounts.

Like other SaaS (software-as-a-service) Web-hosted office collaboration and communications suites, Apps is an alternative to applications that are run on customers' own hardware and managed by their IT staffs.

SaaS suites like Apps are generally much cheaper, require little or no maintenance by IT departments and are designed for Web-based workgroup collaboration.

However, customers must understand that they are trading off a level of control. If the vendor experiences problems in its data center, the performance and availability of the applications will be affected. In those cases, IT and business administrators must simply wait for the vendor to solve its problems.